Aikido (the art of weaponless self-defense) (合気道)
"Aikido" is a modern martial art founded by Morihei UESHIBA early in the Showa period. It's a comprehensive martial art centered around taijutsu (a method of using the body for self-defense), based on the ancient Japanese jujutsu (classical Japanese martial art, usually referring to fighting without a weapon), swordplay, Jojutsu (martial art using a cane staff), etc. It is characterized by the belief that 'small can beat big' regardless of body build or strength, through the rational use of the body. Harmony with nature, world peace, etc., are its main principles.
('Aikido' other than the one founded by Ueshiba are described in detail in "Regarding the name 'aikido.'"
Summary
History - From establishment to development
The founder of Aikido, Morihei UESHIBA, was born into a wealthy farming family in 1883, in Tanabe-cho, Wakayama Prefecture (the present-day Tanabe City). Having studied jujutsu from the Kito-ryu school, Yagyushingan-ryu school, etc., in his youth, he later became a disciple of Sokaku TAKEDA of Daito-ryu Aiki Jujutsu (the Daito style of self-defense) during the development of Hokkaido in 1915, and was accepted as a substitute instructor in 1922. In 1917, he joined the religious group Oomoto, and continued his own training in Ayabe City and Kameoka City in Kyoto while teaching 'Aikibudo' with his nephew Noriaki INOUE (founder of the martial art called Shinei Taido) in the area.
The reputation of this 150cm martial artist who, with his small build, performed peculiar techniques, attracted attention in Tokyo, and in 1927 he moved there with support from the full admiral Isamu TAKESHITA and others. He established Kobukan dojo in 1931 and Aikikai in 1940. Kobukai (皇武会) was renamed as 'Aikikai' in 1948, and since then the name 'Aikido' has been used.
(->The start of Ueshiba 'aikido') With this, Morihei became the first aikido 'Doshu,' and after his death he was referred to as the 'Founder.'
Aikido, which had until then only been taught to a limited number of people in the wealthy class, was disclosed to the public after the war by Kisshomaru UESHIBA, the third son of Morihei, who later became the second Doshu, and subsequently the practice gained many disciples.
During the war, Morihei taught martial arts at Rikugun Nakano Gakko (Military Army Nakano School), Naval War College, etc., upon request by the military. After the war, it greatly influenced the techniques of the combat skill of the Self-Defense Forces and taihojutsu (arresting art) of the police, and training continues today among riot police, etc.
The Aikikai Foundation established by Morihei was succeeded by the second Doshu, Kisshomaru UESHIBA, and is currently represented by the third Doshu, Moriteru UESHIBA, who is the second son of Kisshomaru. Most of today's 1,000,000 domestic aikido practitioners are members of Aikikai, and are the majority or mainstream in the Aikido world. Meanwhile, there are multiple organizations and factions that had separated from Morihei's disciples or Aikikai ("major factions").
As a result of the efforts by Morihei's disciples (beginning in the 1950s) to spread it abroad, it spread globally to Europe, the Americas, Southeast Asia, etc., and Aikikai alone has branch training halls in about 80 countries. Some countries, such as France, have more aikido practitioners than there are in Japan. In 1976, the International Aikido Federation (IAF), an affiliate of Aikikai, was established, and the IAF became an official member of the General Association of International Sports Federations (GAISF), participating in all the World Games since 1989.
Characteristics of techniques and training
* This is described based on Aikikai, which is the majority faction.
Through the rational use of the body, it is believed that 'small can beat big' regardless of body build or strength, and that with throwing techniques and grappling one's opponent can be controlled without being hurt.
(-> "Forms of techniques," "Aiki and breath power," "Debate on its effectiveness as an 'art of self-defense'")
It is centered around kata (a form) training in pairs. It generally consists of throwing techniques and joint-locking techniques, and training in striking techniques is scarce.
(-> "Forms of training")
There are no matches.
(-> "Major factions")
It employs the grading system of kyu and dan.
The aikido clothing is similar to that of judo (a Japanese art of self-defense) and karate (a traditional Japanese martial art), with white bleached tubular sleeves and an open-front top, and a bleached-white trouser-shaped loincloth. An adult beginner wears a white belt, and a rank-holder wears a black belt and black hakama (formal men's divided skirt).
There is no strictly fixed etiquette.
The health benefits are advocated.
(-> "Aikido as a form of physical fitness")
Principles and spirituality
Compared to other martial arts, spirituality is valued, and it's believed that the spiritual state can be seen in the techniques. This reflects the personality of Morihei, who was involved in Shinto, Oomoto, etc., and aspired to the spiritual world.
The charismatic influence that the existence and thoughts of the founder have toward individual practitioners is strong compared to other martial arts. Serving as a strong background was the fact that many anecdotes describing superhuman feats were told in regard to the martial artist Morihei and his strengths, and these anecdotes were taken as facts by many aikido practitioners.
While being based on martial arts, in principle it denies disputes using force, or winning and losing. Its ideal is to resolve conflict with the enemy through aikido techniques, and to reach a state of realizing 'harmony' and 'loving and protecting all things' in nature and the universe. Based on this principle, Aikikai, the mainstream faction, is dismissive about matches.
It is reputed to be the 'martial art of harmony' and the 'martial art in which there is no conflict.'
Among the disciples of Morihei, there were many grand masters of aikido who were influenced by Tenpu NAKAMURA, who was the first to introduce yoga to Japan, handing down the spirituality-oriented spirit of aikido to the next generation.
Forms of technique and training
The techniques include taijutsu, the art of weaponry (swordplay, Jojutsu), and is a comprehensive martial art assuming cases of multiple opponents. However, in reality the percentage of grandmasters instructing in the art of weaponry isn't high, so most training includes instruction in taijutsu only.
Forms of techniques
The unique use of power and sensation in aikido as a means to efficiently control the opponent without wasting energy is called 'breath power' or 'aiki.'
It is believed that by mastering this one can disable the opponent's attack through the "rational" use of the body "without fighting the force of the opponent," and that 'small can beat big' regardless of age, gender, body build or strength.
In aikido, there is a phrase, 'voluntarily offer what the opponent wants,' and defensive techniques and kaeshi waza (returning the opponent's waza (technique) immediately) are common forms.
By warding off the opponent's direction of attack with unique body movements such as 'irimi' (entering straight into a technique) and 'tenkan' (entering indirectly into a technique) while simultaneously functioning within the opponent's blind spot, one maintains the position and posture to one's advantage.
By breathing in sync with the opponent to maintain the contact point, one leads the opponent's center of gravity and posture in the direction needed for it to collapse via the contact point. However, in doing so, needless force will cause a reflex reaction by the opponent and will create issues such as facing resistance with force, separation of the contact point, etc., thereby interfering with the flow of the technique. Therefore, 'datsuryoku' (relaxation) is especially encouraged.
Additionally, by facing the opponent from a blind spot such as the side or the back, and capturing the opponent along the line extending from one's center, the opponent's center of gravity and posture can be controlled and led to collapse with minimal force.
Throwing techniques or grappling can be performed against the opponent whose posture has lost balance. The techniques do not easily succeed when they are used without this kuzushi (balance breaking).
Such subtlety and series of processes for applying techniques to the opponent through the contact point are called 'musubi' (a link between the attacker and the defender), 'lead' and 'kuzushi,' and are emphasized as important elements of aikido techniques and in connection with the spiritual principle.
Forms of training
Training is generally centered around a yakusoku kumite (prearranged fighting) form of kata training done in pairs, and it is repeated, switching the roles of 'tori' (attacker, the one who applies the technique) and 'uke' (defender, the one to whom the technique is applied).
Randori (free practice) training, as used in judo, is usually not done. It basically starts with several kata for controlling the opponent's wrist, elbow and shoulder joints, then various application techniques and henkawaza (changing from one technique to another) (throwing techniques, grappling, etc.) are acquired through repeated training. Most are standing techniques and sitting techniques performed sitting straight, and newaza ((in wrestling or judo) pinning technique) are rare. Striking ('atemi' (blow to the body)) is commonly used for the sake of diversion, and therefore training doesn't place any emphasis on striking. Kicking techniques and grappling with the legs are basically not used, either.
The basic techniques
Irimi-nage: Irimi (entering straight into a technique) from behind the opponent is used to grab the rear collar and pull the opponent backwards. Place the arm on the opponent's neck and throw the opponent down in the direction he was falling.
Kaiten-nage throw (rotary throw): Hold the opponent's arm and rotate it in a large movement from up to front, front to down, and use that force to lower the opponent's head. When the head is down, hold the head with the other palm; move the rotated arm down, back and up, lift the arm vertically and, fixing the shoulder joint, throw forward. It is said to have been named 'kaiten' because the opponent's arm rotates in a large movement.
Shihonage throw: Hold the opponent's arm, and go under the opponent's arm from outside. The opponent's arm will twist outward, but by bringing the opponent's arm toward the back of the opponent the elbow bends, and the opponent will not be able to use force. Bring it down diagonally, backward.
Kotegaeshi: Take the opponent's wrist and place the other hand on the back of opponent's hand, twisting the wrist while moving the shoulder joint outward and rotating it outward. Bend the elbow joint, rotate the forearm outward, bend the hand joint, throwing diagonally forward, then put the opponent on his/her stomach and hold him/her down.
Ikkyo (aikido's first basic technique): Take the opponent's arm and extend the elbow joint as far as it will go, then place the opponent on his/her stomach and hold him/her down.
Nikyo (aikido's second basic technique): Take the opponent's wrist and twist it; bend the hand joint, and rotate the forearm inward; bend the elbow joint; move the shoulder joint outward, and then place the opponent on his/her stomach and hold him/her down.
Sankyo (aikido's third basic technique): Take the opponent's wrist and twist it upward while turning one's body to rotate the forearm inward; bend the elbow joint 90 degrees, move the shoulder joint outward and rotate it inward, make the opponent stand on his/her toes, then place him/her on his/her stomach and hold him/her down.
(Other major techniques: Yonkyo (aikido's fourth basic technique, gokyo (aikido's fifth basic technique), rokkyo (the aikido's sixth basic technique) (hijigatame (elbow lock)), tenchinage throw, koshinage throw, juji garami (cross-entangling method), sumiotoshi drop (corner drop), kokyunage throw, aikinage throw, aikiotoshi drop (aiki drop), etc.)
(The techniques above are common denominators, and the details vary among the various schools and dojo.
It isn't rare to find that the same technique is referred to by different names, or that different techniques have the same name.)
The names of techniques
The fundamental principle of aikido technique is to respond to the opponent's attack with throws or by grappling.
The names of techniques are a combination of 'the positional relationship of the defender and attacker at the beginning of the technique' or 'the form of attack of the defender at the beginning of the technique' and 'the specific names of techniques described above.'
For example, the defender grabbing the attacker's right wrist with his/her right hand is called 'katate kosa dori' (grabbing one hand across the way), 'naname katate dori' (diagonal, grabbing one hand) or 'ai hanmi katate dori' (same stance, grabbing one hand). The form of attack in which the defender swings down a tegatana (literally, 'hand sword') from directly above the attacker's front side is called 'shomen-uchi strike,' and from each state each of the above techniques can be derived.
Examples:
Katate kosa dori and kokyunage throw
Etc.
Aiki and breath power
Aiki' and 'breath power' are elements of aikido techniques as well as concepts that are important principles of aikido.
Aiki' is a martial-arts term from ancient Japan, originally referring to the state in which force and kamae (posture) are competing. In recent years, influenced by its use in Daito school and aikido, it refers to the techniques and principles of disabling the opponent's attacks by 'matching the "qi"' of oneself to the "qi" (including the will to attack, timing and vector of force) of the opponent, instead of competing against the opponent's force with force, especially in martial arts using bare hands (it is used for its original meaning in kendo (the Japanese art of fencing) and in the ancient arts of weaponry).
In aikido, going beyond the implications above, it came to stand for the spiritual principle of 'realizing the ideal state through harmony with the principles of nature and the universe (equivalent to "qi"), in which there is no conflict with others.'
(In Morihei's words, 'Aiki is love.')
Breath power' is a coined termed created by Morihei in the process of establishing his martial art, and it's an expression of 'aiki' through Morihei's unique point of view.
While 'aiki' in aikido is mainly used in the sense of a principle, 'breath power' is mainly used to mean 'a source of power for techniques.'
There are many theories as to which specific power this 'breath power' refers. Morihei often borrowed terms from Shinto when describing the principles and rationale of Aikido to his disciples, and because this was a mystic and abstract expression it led to various interpretations in later years.
For example, there are various opinions such as 'the power of the breathing (muscles),' 'power of "qi,"' the 'way of using power in a natural and subconscious way like actual breathing,' and 'unification of the power of the entire body.'
Aiki and breath power are commonly thought of as mysterious techniques that enable a small, elderly man to easily throw and hold down a succession of tough men, thus raising the doubt of suspicion in their regard.
In order to clarify aiki and breath power as concrete technical principles, there have been many attempts to explain them from various angles such as datsuryoku, the use of body weight, the shifting of one's center of gravity, the abdomen and lower back inner muscles, the leverage theory, the use of illusion and reflex, and psychological manipulation, but research from the perspective of empirical science has not been sufficient. Additionally, opinions are divided over whether the "aiki" of Aikido and the "aiki" of other martial arts such as Daito school are the same or different. However, the opinions of the various schools are common in regard to the following.
Datsuryoku' is the condition for exercising aiki and breath power. There is an emphasis on attitude and breathing. There is an emphasis on consciousness of the inner part of the lower abdomen, just beneath the navel.
The art of weaponry in aikido
Regarding the art of weaponry in aikido, views differ as described below, depending on the grandmaster.
The taijutsu of Aikido includes the rationale of swordplay and Jojutsu.
(There is no need to specially train in swordplay and Jojutsu.)
Taijutsu alone is not sufficient, but training in the art of weaponry such as swordplay and Jojutsu is necessary.
(Some grandmasters train in 'aikiken' (the sword technique of aikido) and 'aikijo' (staff technique of aikido), while other grandmasters train in swordplay and the jojutsu of other schools, as interpreted under the aikido rationale.)
Morihei UESHIBA studied the art of weaponry in Iwama with Morihiro SAITO, and in regard to aikiken and aikijo, which Saito organized based on Morihei's weapon techniques, some grandmasters position them as the art of weaponry for aikido while other grandmasters disapprove of them, claiming that aikiken and aikijo include interpretation by Saito.
Enbukai (public demonstration)
In aikido, for which matches aren't held, enbukai is held to improve individual skills and promote it to the general public. Enbu means to perform predetermined techniques in order, and the same technique can reveal the personality of the performers, with some performing in a fierce, slamming manner, while others perform quietly and matter-of-factly. Subsequent to the war, since the second Doshu, Kisshomaru UESHIBA, many performers began to gather for performances, just as is done today. When Morihei learned that Kisshomaru had decided to hold an enbukai on the rooftop of a department store to promote aikido, he objected strongly. Until then, enbu had been performed by Morihei, and it was inconceivable that an inexperienced performer would present techniques in public. Eventually, the enbukai was held at Kisshomaru's insistence, and today the factions hold enbukai regularly. Among them, the 'All Japan Aikido Demonstration,' which is held annually at the Nippon Budokan by Aikikai Foundation, is the largest enbukai in Japan.
Meanwhile, the purpose of enbu is to show techniques to the audience, so the defender knows what technique is next, and inexperienced defenders may be actively attuned to the thrower. Some audience who see it criticize aikido as bogus, cozy or fixed.
The difference from Daito-ryu Aiki Jujutsu (the Daito style self-defense technique)
The techniques and training methods used have generally been inherited from Daito-ryu Aiki Jujutsu. Daito-ryu Aiki Jujutsu and Aikido both apply techniques in a circular movement, but aikido uses a relatively larger circular movement to apply techniques. This is believed to be a conclusion that Morihei reached through training.
Some categorize Daito school as linear and Aikido as circular in movement, but depending on the stage of training or the type of technique, some techniques in aikido require linear movements and some techniques in Daito school can't be used without rotating in a circle; therefore, one can't say for certain which is which.
Technically, some refer to Aikido as Daito-ryu Aiki Jujutsu, or the Ueshiba method, viewing it as one faction of Daito-ryu Aiki Jujutsu. In fact, Daito-ryu Aiki Jujutsu has various factions, and it's possible to view Aikido as one such faction. However, the clearest difference between Daito-ryu Aiki Jujutsu and Aikido is in the ideologies of how they position the purpose and meaning of martial arts.
Aikido, as handed down by Morihei, teaches many martial arts using weapons such as swords and cane staffs, but it draws its lineage from the ancient martial arts and has a strong sense of loving and protecting all things, as well as to contribution to the formation of the universe. This is believed to be from the days of Oomoto aikido, and the martial art known as Shinei Taido has a similar ideology. It is believed that most of the many rough techniques taught in Daito school, such as reverse joint techniques, stamping techniques and grappling using the feet, are omitted from Aikido due to this ideology.
Exchanges with judo
Jigoro KANO, the founder of Judo, once visited the dojo of Morihei UESHIBA, and Kano, who was fascinated by the techniques, instructed several high-ranking practitioners from the Kodokan Judo Institute--such as Minoru MOCHIZUKI, Aritoshi MURASHIGE and Yoshio SUGINO--to practice Aikido. Thus the exchanges between aikido and the judo of the Kodokan Judo Institute were relatively active.
It is said that when Jigoro KANO saw Morihei UESHIBA's aikido he shouted, "This is what I've been searching for!"
Powerful disciples of Morihei, such as Gozo SHIODA, Kenji TOMIKI and Minoru MOCHIZUKI, were judo yudansha (judo black-belts) before becoming Ueshiba's disciples. Tomiki and Mochizuki, in particular, continued their activities as judo practitioners even after becoming high-caliber disciples of Ueshiba, and their philosophies were reflective of both aikido and judo.
Exchanges with kendo
Morihei UESHIBA allowed kendo training in his dojo 'Kobukan' for the study of swordplay. Actual training was conducted by Kiyoshi NAKAKURA (who was at the time Morihei's adopted son-in-law), Junichi HAGA and Gorozo NAKAJIMA: These comprised the so-called 'trio of Yushinkan,' who were the three high-caliber disciples of a close friend, Hiromichi NAKAYAMA (of the Shindo-Munen school of swordsmanship).
Aikido as a means of physical fitness
In Aikikai-affiliated dojo, at the start of training it is customary to perform a method of discipline called 'aiki taiso,' as invented by Morihei. By stretching various parts of the body, it serves as a warm-up exercise before training, but some misogi (purification ceremony) gyoho (method of ascetic practice) of Shinto such as 'torifune' (bird rowing misogi exercise) and 'furutama' (soul shaking) are included, and it's believed that this alone is effective for the "discipline of qi" and the "discipline of breath power." Additionally, the 'Nishi System of Health Engineering' by Katsuzo NISHI, the director of the Aikikai Foundation, is employed.
In order to promote aikido to the general public, it was often promoted as 'health exercise' and 'recreation.'
Training in aikido repeats techniques using the same movements for the left and right, repeating them the same number of times, so it effectively resolves distortion between the left and right sides of the body.
Rolling on the tatami mat for ukemi (falling techniques) improves the blood circulation. Additionally, by learning ukemi one can prevent injury due to falling.
The application of joint-locking techniques has the effect of stretching, and it prevents stiff shoulder.
Because matches aren't held, there is no need for excessive training, and the discipline of the legs and loins can be done naturally depending on one's age and strength.
Morihei himself spoke of the health benefits of aikido using unique religious expressions, saying that 'aikido is a "misogi" that removes the "impurities" from the body by improving the blood circulation, correcting the bone structure and adjusting the flow of "qi" in the body through moderate exercise.'
Another unique point rarely seen in other martial arts is that aikido links its religious ceremonial nature with physical fitness and positions it as one of the purposes of training.
Debate regarding its effectiveness as an 'art of self-defense'
Because it's a martial art that controls the opponent without depending on ordinary muscular strength or force, aikido has been advertised as being 'effective as an art of self-defense for powerless women,' and though many consider it as such, some are questioning this today.
Reasons for the negative opinions include the following, questioning the idea of considering aikido as a common art of self-defense.
The form of daily training in the majority of the dojo is focused entirely on kata training. Kata training is a method in which the attacker (tori) and defender (uke) are predetermined, and movements somewhat known to both parties are performed. In this training, the uke doesn't seriously respond but instead moves in such a way that he/she is more easily attacked. When practicing kaeshi waza (a technique in which the uke attacks first, and the tori handles it and attacks), the first attack by the uke is predetermined. It is questionable whether the skill to respond to actual free offense and defense (the opponent resists, and the opponent's attack is unknown) is built solely through training in which the opponent doesn't resist and the opponent's attack is known in advance.
Additionally, with regard to this some say that aikido doesn't require force because 'in training, only kata training where the opponent doesn't resist is performed, so daily training doesn't require force and people who aren't strong can perform as well,' but not because 'aikido's techniques are superior as an art of self-defense or a martial art, allowing one to throw, grapple and control the opponent without force.'
Furthermore, the techniques of kata training such as 'katatedori (the attacker grabs the opponent's wrist), 'shomen-uchi strike' (the attacker swings down a tegatana to hit) are forms of response to attacks that are unlikely in today's actual fights (this is due to the fact that old-style jujutsu, which was the origin of aikido, was from the age when a sword on a belt was used, and such training simulates scenes such as 'holding down the hand that was placed on the grip of the sword to draw it, i.e., katatedori' and 'being swung down a sword, i.e., shomen-uchi strike).'
Additionally, in aikido's kata training techniques there are assumptions such as 'the defender doesn't let go of the grip even if he/she is in a somewhat disadvantaged position,' 'when the defender is attacked on his back side, he/she turns around on the front foot and follows the opponent,' or 'when balance is lost slightly, perform ukemi even if it feels as if it's tolerable (be thrown),' which are unthinkable in today's actual fights.
(These also are believed to have the following reasons behind them: 'do not let go of the grip -> it is absolutely disadvantageous to let go, since he/she is holding down a sword,' 'turn around on the front foot and follow, i.e., the front foot is the stem, because the center of gravity is toward the front when holding a sword and it's absolutely disadvantageous to be at a halfway distance with an opponent bearing a sword,' 'ukemi when losing balance, i.e., it's better to gain a big distance using ukemi than to struggle to recover one's position when the opponent has a sword.')
It can be imagined that techniques by which to control the opponent without depending on muscular strength or force can be very advanced and difficult, but it's normal that advanced or difficult techniques will take considerable time to learn, and society's demand for quick training in a crash course in the art of self-defense can't be met.
lMeanwhile, the Japan Aikido Association (Tomiki school) practices randori (throwing practice with both partners trying to throw each other) with short swords in mind, and it's considered an art of self-defense against blades. Among factions that don't practice randori, Yoshinkan aikido and Iwama-shinshin-aikishurenkai (Iwama school) actively teach aikido as an art of self-defense. There are various other aikido practitioners and independent factions that study the possibilities of aikido as an art of self-defense, and since there are techniques and movements in mixed martial arts and karate that are common to those of aikido, some consider it useful as an art of self-defense.
Major factions
* In the order of the year they became independent, 'name of organization (name of style, common name): year of independence, founder'
Aikikai ('Aikido'): 1940 as Kobukai Foundation, 1948 as Aikikai Foundation, Morihei UESHIBA
The largest faction in the world of aikido, founded by the founder of aikido, Morihei UESHIBA. It is believed to account for 80% of the aikido population.
Aikido Yoshinkai Foundation ('Yoshinkan aikido'): 1956, Gozo SHIODA
It was established by Gozo SHIODA, a high-caliber disciple of Morihei. Their motto is 'aikido for actual battle,' and it's taught today as a requisite subject for the riot police of the Keishi-cho (the Tokyo Metropolitan Police Department).
Yoseikan ('Yoseikan aikido'): 1963, Minoru MOCHIZUKI
It was established by Minoru MOCHIZUKI, a high-caliber disciple of Morihei. It incorporated elements of judo and karate into aikido. (Yoseikan currently advocates a new martial art called 'Yoseikan budo,' which is independent from aikido.
In 2000, the 'Budo Seifukai Federation' separated from Yoseikan in order to take over 'Yoseikan aikido.')
Manseikan aikido: 1969, Kanshu SUNADOMARI
It was established by Kanshu SUNADOMARI, a high-caliber disciple of Morihei. It eventually spread throughout the Kyushu region.
Japan Aikido Association ('Shodokan aikido,' 'Tomiki ryu'): 1974, Kenji TOMIKI
It was established by Kenji TOMIKI, a high-caliber disciple of Morihei. It incorporates randori, referring to judo, and is popular among some university aikido groups.
Ki Society ('Shin Shin Toitsu Aikido' (mind and body unification aikido)): 1974, Koichi TOHEI
It was established by Koichi TOHEI, who was a high-caliber disciple of Morihei and the head instructor of the Aikikai Foundation.
He valued 'qi.'
Shoot-Aikido: 1991, Fumio SAKURAI
It was established by Fumio SAKURAI, a high-caliber disciple of Gozo SHIODA. It features kumite-shiai (sparring match) in which striking is allowed, and participation by other factions is accepted.
Iwama-shinshin-aikishurenkai ('Iwama school aikido,' 'Iwama style'): 2004, Hitohiro SAITO
It was established by Hitohiro SAITO, the son of Morihiro SAITO, who was a high-caliber disciple of Morihei.
He was influential, teaching aikido from the later years of Morihei and including 'aikiken and aikijo.'
Regarding the name 'aikido'
Today, 'aikido' generally refers to aikido as founded by Morihei UESHIBA, but in fact Morihei wasn't the first to use the name 'aikido,' and another line of 'aikido' exists. Additionally, it's used as a common noun that vaguely refers to "aiki martial arts" in general.
Dai Nippon Butoku-kai aikido
It is believed that this name first appeared in 1942, in 'Aikido-bu' (aikido division) established in the government extra-departmental organization Dai Nippon Butoku-kai, and that 'Dai Nippon Butoku-kai aikido' was established as a "comprehensive martial arts" (martial arts integrating taijutsu, swordplay, etc).
Morihei, at that time, was asked by Dai Nippon Butoku-kai to cooperate in the establishment of a comprehensive martial arts department, and in response he referred Minoru HIRAI, who was a 'general director' at the Kobukan dojo. Hirai was appointed as the manager of Dai Nippon Butoku-kai, and was placed in charge of operating the aikido-bu.
After the war in 1945, Hirai established 'Korindo aikido' to pass down Dai Nippon Butoku-kai aikido, and it was considered a separate lineage from Ueshiba school.
The start of Ueshiba's 'aikido'
Morihei began using the name 'aikido' in 1948, since the establishment of Aikikai (prior to which he had used the names 'Aikibudo,' 'Dai Nippon Kyokuryu Jujutsu,' etc.). Regarding the story behind the name 'aikido,' shortly before his death Morihei said in a media interview that someone in the Ministry of Education back then had suggested it.
Major forms of aikido other than the Ueshiba lineage
The Korindo aikido of Minoru HIRAI
Some in Daito school, etc., use it as a common name.
Takeda school Nakamura group aikido and Nihonden Mugen school aikido, which are said to be successors of Takeda school Aiki no jutsu.
Hapkido (written in Chinese characters as '合気道'), of the Republic of Korea